feat(sdk): plain text policy support

Author: sujankota

cli/src/cli.ts

@@ -23,6 +23,7 @@ import { webcrypto } from 'crypto';
 import * as assertions from '@opentdf/sdk/assertions';
 import { attributeFQNsAsValues } from '@opentdf/sdk/nano';
 import { base64 } from '@opentdf/sdk/encodings';
+import { PolicyType} from '@opentdf/sdk';
 import { type CryptoKey, importPKCS8, importSPKI } from 'jose'; // for RS256
 
 type AuthToProcess = {
@@ -309,12 +310,16 @@ async function parseCreateZTDFOptions(argv: Partial<mainArgs>): Promise<CreateZT
   return c;
 }
 
-async function parseCreateNanoTDFOptions(argv: Partial<mainArgs>): Promise<CreateZTDFOptions> {
+async function parseCreateNanoTDFOptions(argv: Partial<mainArgs>): Promise<CreateNanoTDFOptions> {
   const c: CreateNanoTDFOptions = await parseCreateOptions(argv);
   const ecdsaBinding = argv.policyBinding?.toLowerCase() == 'ecdsa';
   if (ecdsaBinding) {
     c.bindingType = 'ecdsa';
   }
+
+  if (argv.policyType) {
+    c.policyType = PolicyType[argv.policyType as keyof typeof PolicyType]
+  }
   // NOTE autoconfigure is not yet supported in nanotdf
   delete c.autoconfigure;
   log('DEBUG', `CreateNanoTDFOptions: ${JSON.stringify(c)}`);
@@ -521,6 +526,13 @@ export const handleArgs = (args: string[]) => {
           description: 'TDF spec version for file creation',
           default: tdfSpecVersion,
         },
+        policyType: {
+          group: 'Encrypt Options:',
+          desc: 'Policy type for NanoTDF: EmbeddedEncrypted or EmbeddedText',
+          type: 'string',
+          choices: ['EmbeddedEncrypted', 'EmbeddedText'],
+          default: 'EmbeddedEncrypted',
+        },
       })
 
       .options({

lib/src/index.ts

@@ -6,3 +6,4 @@ export { PlatformClient, type PlatformClientOptions, type PlatformServices } fro
 export * from './opentdf.js';
 export * from './seekable.js';
 export * from '../tdf3/src/models/index.js';
+export { default as PolicyType } from './nanotdf/enum/PolicyTypeEnum.js';

lib/src/nanoclients.ts

@@ -14,15 +14,18 @@ import { fetchECKasPubKey } from './access.js';
 import { type ClientConfig } from './nanotdf/Client.js';
 import { ConfigurationError } from './errors.js';
 import { type AttributeObject } from '../tdf3/src/models/attribute.js';
+import PolicyType from './nanotdf/enum/PolicyTypeEnum.js';
 
 // Define the EncryptOptions type
 export type EncryptOptions = {
   ecdsaBinding: boolean;
+  policyType?: PolicyType;
 };
 
 // Define default options
 const defaultOptions: EncryptOptions = {
   ecdsaBinding: false,
+  policyType: PolicyType.EmbeddedEncrypted,
 };
 
 /**
@@ -100,6 +103,14 @@ export class NanoTDFClient extends Client {
     const ephemeralKeyPair = await this.ephemeralKeyPair;
     const initializationVector = this.iv;
 
+    const mergedOptions: EncryptOptions = { ...defaultOptions, ...options };
+    if (
+      mergedOptions.policyType !== PolicyType.EmbeddedEncrypted &&
+      mergedOptions.policyType !== PolicyType.EmbeddedText
+    ) {
+      throw new ConfigurationError('Invalid policy type');
+    }
+
     if (typeof initializationVector !== 'number') {
       throw new ConfigurationError(
         'NanoTDF clients are single use. Please generate a new client and keypair.'
@@ -146,14 +157,14 @@ export class NanoTDFClient extends Client {
     payloadIV[10] = lengthAsUint24[1];
     payloadIV[11] = lengthAsUint24[0];
 
-    const mergedOptions: EncryptOptions = { ...defaultOptions, ...options };
     return encrypt(
       policyObjectAsStr,
       this.kasPubKey,
       ephemeralKeyPair,
       payloadIV,
       data,
-      mergedOptions.ecdsaBinding
+      mergedOptions.ecdsaBinding,
+      mergedOptions.policyType
     );
   }
 }
@@ -283,7 +294,8 @@ export class NanoTDFDatasetClient extends Client {
         ephemeralKeyPair,
         ivVector,
         data,
-        this.ecdsaBinding
+        this.ecdsaBinding,
+        mergedOptions.policyType,
       );
 
       // Cache the header and increment the key iteration

lib/src/nanotdf/encrypt.ts

@@ -18,6 +18,7 @@ import {
 import { KasPublicKeyInfo } from '../access.js';
 import { computeECDSASig, extractRSValuesFromSignature } from '../nanotdf-crypto/ecdsaSignature.js';
 import { ConfigurationError } from '../errors.js';
+import PolicyType from './enum/PolicyTypeEnum.js';
 
 /**
  * Encrypt the plain data into nanotdf buffer
@@ -28,14 +29,16 @@ import { ConfigurationError } from '../errors.js';
  * @param iv
  * @param data The data to be encrypted
  * @param ecdsaBinding Flag to enable ECDSA binding
+ * @param policyType Policy type to use for the nanotdf
  */
 export default async function encrypt(
   policy: string,
   kasInfo: KasPublicKeyInfo,
   ephemeralKeyPair: CryptoKeyPair,
   iv: Uint8Array,
   data: string | ArrayBufferLike,
-  ecdsaBinding: boolean = DefaultParams.ecdsaBinding
+  ecdsaBinding: boolean = DefaultParams.ecdsaBinding,
+  policyType?: PolicyType
 ): Promise<ArrayBuffer> {
   // Generate a symmetric key.
   if (!ephemeralKeyPair.privateKey) {
@@ -54,23 +57,32 @@ export default async function encrypt(
   // Auth tag length for policy and payload
   const authTagLengthInBytes = authTagLengthForCipher(DefaultParams.symmetricCipher) / 8;
 
-  // Encrypt the policy
-  const policyIV = new Uint8Array(iv.length).fill(0);
-  const policyAsBuffer = new TextEncoder().encode(policy);
-  const encryptedPolicy = await cryptoEncrypt(
-    symmetricKey,
-    policyAsBuffer,
-    policyIV,
-    authTagLengthInBytes * 8
-  );
+  let policyContent: Uint8Array;
+  if (policyType === PolicyType.EmbeddedText) {
+    // Store policy as plain text
+    policyContent = new TextEncoder().encode(policy);
+  } else {
+    // Encrypt the policy
+    const policyIV = new Uint8Array(iv.length).fill(0);
+    const policyAsBuffer = new TextEncoder().encode(policy);
+    policyContent = new Uint8Array(
+      await cryptoEncrypt(
+        symmetricKey,
+        policyAsBuffer,
+        policyIV,
+        authTagLengthInBytes * 8
+      )
+    );
+  }
+
 
   let policyBinding: Uint8Array;
 
   // Calculate the policy binding.
   if (ecdsaBinding) {
     const curveName = await getCurveNameFromPrivateKey(ephemeralKeyPair.privateKey);
     const ecdsaPrivateKey = await convertECDHToECDSA(ephemeralKeyPair.privateKey, curveName);
-    const ecdsaSignature = await computeECDSASig(ecdsaPrivateKey, new Uint8Array(encryptedPolicy));
+    const ecdsaSignature = await computeECDSASig(ecdsaPrivateKey, policyContent);
     const { r, s } = extractRSValuesFromSignature(new Uint8Array(ecdsaSignature));
 
     const rLength = r.length;
@@ -84,15 +96,15 @@ export default async function encrypt(
     policyBinding[1 + rLength] = sLength;
     policyBinding.set(s, 1 + rLength + 1);
   } else {
-    const signature = await digest('SHA-256', new Uint8Array(encryptedPolicy));
+    const signature = await digest('SHA-256', policyContent);
     policyBinding = new Uint8Array(signature.slice(-GMAC_BINDING_LEN));
   }
 
   // Create embedded policy
   const embeddedPolicy = new EmbeddedPolicy(
-    DefaultParams.policyType,
+    policyType ?? PolicyType.EmbeddedEncrypted,
     policyBinding,
-    new Uint8Array(encryptedPolicy)
+    policyContent
   );
 
   if (!ephemeralKeyPair.publicKey) {

lib/src/nanotdf/index.ts

@@ -8,3 +8,4 @@ export { default as encrypt } from './encrypt.js';
 export { default as encryptDataset } from './encrypt-dataset.js';
 export { default as getHkdfSalt } from './helpers/getHkdfSalt.js';
 export { default as DefaultParams } from './models/DefaultParams.js';
+export { default as PolicyType } from './enum/PolicyTypeEnum.js';

lib/src/opentdf.ts

@@ -92,6 +92,9 @@ export type CreateNanoTDFOptions = CreateOptions & {
    * to generate a signature for each element. When absent, the nanotdf is unsigned.
    */
   signingKeyID?: string;
+
+  /** The type of policy to embed in the NanoTDF. */
+  policyType?: PolicyType;
 };
 
 /** Options for creating a NanoTDF collection. */
@@ -759,14 +762,12 @@ class Collection {
     if (opts.ecdsaBindingKeyID) {
       throw new ConfigurationError('custom binding key not implemented');
     }
-    switch (opts.bindingType) {
-      case 'ecdsa':
-        this.encryptOptions = { ecdsaBinding: true };
-        break;
-      case 'gmac':
-        this.encryptOptions = { ecdsaBinding: false };
-        break;
-    }
+    
+    // Initialize encryptOptions with policyType if provided
+    this.encryptOptions = { 
+      ecdsaBinding: opts.bindingType === 'ecdsa',
+      policyType: opts.policyType
+    };
 
     const kasEndpoint =
       opts.defaultKASEndpoint || opts.platformUrl || 'https://disallow.all.invalid';